Roche’s multiple sclerosis win puts more pressure on Sanofi

Liver toxicity is a class effect of BTK inhibitors, according to Sanofi, whose tolebrutinib is the lead multiple sclerosis project with this pharmacology. However, Roche’s fenebrutinib and Novartis’s remibrutinib have so far avoided this issue. Today Roche reported topline phase 2 data on its candidate, saying fenebrutinib significantly reduced the number of new gadolinium-enhancing T1 brain lesions versus placebo. Safety will be closely watched when full results are presented, but Roche said this was consistent with previous trials, with no new concerns. And Sanofi still sees a future for tolebrutinib, which remains on partial clinical hold in the US. During a first-quarter call its chief medical officer, Dietmar Berger, said the group was working on a risk-mitigation strategy, and noted that it had not seen further liver tox since close monitoring was introduced. “If the efficacy data is what we hope the monitoring is really not a barrier to uptake,” chief exec Paul Hudson added. Phase 3 could read out by year end. The fourth quarter should also see data on Merck KGaA’s rival evobrutinib, which also went on partial FDA hold in April. Results should shed light on whether the benefits indeed outweigh the risks.